1. Field of the Invention
The present invention relates to an automatic tensioning and damping element for endless chain drives, wherein the application of the automatic tensioning and damping element is universal for chain drives to be tensioned diametrically.
2. Brief Description of the Background of the Invention Including Prior Art
An automatic tensioning and damping element is known from the German Democratic Patent document DD-WP 275,166. The element of the reference is a ring without an axis and made of an elastic material, where the ring is elastically deformable between the shape of a concentric ring and the shape of a cassinic curve with an ellipse-like form, and where the ring is adapted in its shape to the chain.
This tensioning and damping element is disposed between the strands of the chain drives, engages with its chain crown into the chain drives and thus secures automatically its position in the chain drive and tensions diametrically. The tensioning and damping element rolls without an axis and synchronously with the speed of the chain between the moving strands. The dilations of the chains are balanced by having the pretensioned tensioning and damping element aspire to assume the shape of a concentric ring, wherein the distance between the secondary summits of the tensioning and damping element is enlarged based on the symmetry center at a maximum of up to the diameter of the concentric ring. This function is performed in opposite by decreasing the distance between the secondary summits for damping of load peaks.
Advantageously, such tensioning and damping elements are produced of materials with defined elastic, visco-elastic, and plastic deformation parameters.
The disadvantage of this known automatic tensioning and damping element includes that back distortion energy is used during the rolling. This back-distortion energy is not necessary in every case for the instantaneous suppression of longitudinal vibrations and of larger transverse vibrations of the chain drive.
The technical cause of this disadvantage is associates with the rolling motion, where the rolling motion is synchronous with the chain speed of the automatic tensioning and damping element, is from the position-securing engagement of the tooth profile into the strand. Depending on the material, the plastic deformation part as well as, in case of a corresponding trailing of the material-dependent visco-elastic restoring relative to the speed-dependent back distortion, the visco-elastic deformation part of the ring has to be formed back.